1. Technical Field of the Invention
The present invention generally relates to a label printer, method, and label and more particularly to a printing control apparatus for a label printer used in department stores and supermarkets for automatically printing indicia, e.g., a commodity name, price, manufacturing date, store name and bar code on a label which is adapted to be adhered to a corresponding commodity. Even more particularly, the present invention relates to an improved printing control apparatus for a label printer in which a number of thermal elements are disposed in a transverse direction to form a thermal head which is adapted to be brought into contact with the printable surface of a thermosensitive coloring label, and whereby the thermal elements are energized in accordance with printing information received and wherein either the thermal head or the label is moved parallel to the printing surface and perpendicularly to the transverse alignment of the thermal elements in order to print specified or desired marks and other indicia on the label.
The present invention also relates to a method of printing using the apparatus and to a label utilized in conjunction with the above-referred to label printer.
2. Description of the Prior Art
In conventional label printers of this general type, a strip of base paper on which labels are separably adhered at predetermined intervals or spacings is fed intermittently so that each label, when positioned at the appropriate position for printing, will be brought into contact with a thermal head having a predetermined pressure applied thereto in order that marks can be printed on the printing surface of the label.
In such arrangements, the thermal head is in continuous contact either with a label or with a strip of base paper on which the labels are adhered, the latter in areas in which no labels are adhered. Consequently, the thermal head is easily worn out and contaminated, often resulting in poor print quality and printer failure.
In such label printers, the heat of the thermal head which is needed for printing is generated by current conduction and must be dissipated appropriately through a label, which is made of thermosensitive coloring paper.
However, if no labels remain at the end of a strip, if a label is for any reason missing from the strip, or if the pressing device malfunctions and thereby fails to press the thermal head to the label in an appropriate fashion, the thermal head will be spaced from the label at the time of printing. Accordingly, the heat of the thermal head will not be dissipated through a label, and damage will thereby be caused to the thermal head due to overheating. Such abnormal operation not only shortens the service life of the thermal head, but also causes poor quality printing on the labels.
Moreover, if the transportation device for moving the strip and labels does not operate normally, e.g., due to a slip or a jam of a label, or if for some other reason the label is not fed smoothly through the machine, the thermal head will continue to print at the same location of a label for a relatively long period of time, thereby causing undesireable heat accumulation at the head, which in turn can cause damage to the head through overheating.
Labels used in conjunction with the above-identified conventional label printers are made from paper or synthetic resin film, and fixed printed items, including frames, store name and address are often printed in advance, any and all variable print items, including the unit price, quantity, weight, price and bar code being printed at each store at a later time using a printer. The reason for separate printing is that it is not possible for prior art printers to print colorful frames, store names and addresses for attracting customers on labels which are made of paper or synthetic resin film.
Therefore, conventional labels have been required to be partially printed in advance, which is expensive, and therefore do not generally allow for the printing of colorful descriptions for specially advertised commodities.